<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
      .box{
        margin: 300px auto;
        width: 200px;
        height: 200px;
        background-color: yellowgreen;
        transition: all 3s;
        /* 旋转位置选取值中间要用空格进行分隔，50% 50% 为中心点 */
        /* transform-origin:left bottom; */
        /* transform-origin: 30% 30%; */
        /* 相对于元素本身的X Y 值进行旋转 */
        transform-origin: 100px 50px;
      }
      .box:hover{
        transform: rotate(180deg);
      }
    </style>
</head>
<body>
    <div class="box"></div>
</body>
</html>